 /*******************************************************************************
  * Copyright (c) 2000, 2007 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.update.internal.ui.parts;
 /**
  * @version 1.0
  * @author
  */
 import org.eclipse.core.runtime.Assert;
 import org.eclipse.jface.dialogs.*;
 import org.eclipse.jface.dialogs.Dialog;
 import org.eclipse.jface.resource.*;
 import org.eclipse.swt.*;
 import org.eclipse.swt.dnd.*;
 import org.eclipse.swt.graphics.*;
 import org.eclipse.swt.layout.*;
 import org.eclipse.swt.widgets.*;

 /**
  * Utility class to simplify access to some SWT resources.
  */
 public class SWTUtil {

     /**
      * Returns the standard display to be used. The method first checks, if
      * the thread calling this method has an associated disaply. If so, this
      * display is returned. Otherwise the method returns the default display.
      */
     public static Display getStandardDisplay() {
         Display display;
         display = Display.getCurrent();
         if (display == null)
             display = Display.getDefault();
         return display;
     }

     /**
      * Returns the shell for the given widget. If the widget doesn't represent
      * a SWT object that manage a shell, <code>null</code> is returned.
      *
      * @return the shell for the given widget
      */
     public static Shell getShell(Widget widget) {
         if (widget instanceof Control)
             return ((Control) widget).getShell();
         if (widget instanceof Caret)
             return ((Caret) widget).getParent().getShell();
         if (widget instanceof DragSource)
             return ((DragSource) widget).getControl().getShell();
         if (widget instanceof DropTarget)
             return ((DropTarget) widget).getControl().getShell();
         if (widget instanceof Menu)
             return ((Menu) widget).getParent().getShell();
         if (widget instanceof ScrollBar)
             return ((ScrollBar) widget).getParent().getShell();

         return null;
     }

     /**
      * Returns a width hint for a button control.
      */
     public static int getButtonWidthHint(Button button) {
         if (button.getFont().equals(JFaceResources.getDefaultFont()))
             button.setFont(JFaceResources.getDialogFont());
         PixelConverter converter= new PixelConverter(button);
         int widthHint= converter.convertHorizontalDLUsToPixels(IDialogConstants.BUTTON_WIDTH);
         return Math.max(widthHint, button.computeSize(SWT.DEFAULT, SWT.DEFAULT, true).x);
     }

     /**
      * Sets width and height hint for the button control.
      * <b>Note:</b> This is a NOP if the button's layout data is not
      * an instance of <code>GridData</code>.
      *
      * @param button the button for which to set the dimension hint
      */
     public static void setButtonDimensionHint(Button button) {
         Dialog.applyDialogFont(button);
         Assert.isNotNull(button);
         Object gd = button.getLayoutData();
         if (gd instanceof GridData) {
             ((GridData) gd).widthHint = getButtonWidthHint(button);
         }
     }

     public static void setDialogSize(Dialog dialog, int width, int height) {
         Point computedSize =
             dialog.getShell().computeSize(SWT.DEFAULT, SWT.DEFAULT);
         width = Math.max(computedSize.x, width);
         height = Math.max(computedSize.y, height);
         dialog.getShell().setSize(width, height);
     }
 }

